David could probably do with a practice game to get used to 8th ed and his army, and you could command the Compagnia for that. It would be against myself and my son - who also needs practice games. That way, no pressure at all - it won't be an 'official' game with me taking notes and pictures. Just fun. (Although the official games are fun too!)
There could well then be a 'real' battle soon after, although nothing is certain in our campaign - a lot can happen and it can be quite different to what was thought would happen!